<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* width  宽度 */
        /* height  高度 */
        /* background-color  背景色 */
        .red {
            width: 100px;
            height: 100px;
            background-color: red;
        }
        .orange {
            width: 200px;
            height: 200px;
            background-color: orange;
        }
    </style>
</head>
<body>
    <div class="red">小帅</div>
    <div class="orange">小明</div>
</body>
</html>